From 9f1a122f970dbef5ba3496587f39df5c1853083f Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 24 May 2010 15:41:33 +0800 Subject: [PATCH] KVM: MMU: allow more page become unsync at getting sp time Allow more page become asynchronous at getting sp time, if need create new shadow page for gfn but it not allow unsync(level > 1), we should unsync all gfn's unsync page Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 47 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 37 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ba119dae890e..07673487fd5d 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1220,6 +1220,35 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return __kvm_sync_page(vcpu, sp, true); } +/* @gfn should be write-protected at the call site */ +static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn) +{ + struct hlist_head *bucket; + struct kvm_mmu_page *s; + struct hlist_node *node, *n; + unsigned index; + bool flush = false; + + index = kvm_page_table_hashfn(gfn); + bucket = &vcpu->kvm->arch.mmu_page_hash[index]; + hlist_for_each_entry_safe(s, node, n, bucket, hash_link) { + if (s->gfn != gfn || !s->unsync || s->role.invalid) + continue; + + WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL); + if ((s->role.cr4_pae != !!is_pae(vcpu)) || + (vcpu->arch.mmu.sync_page(vcpu, s))) { + kvm_mmu_zap_page(vcpu->kvm, s); + continue; + } + kvm_unlink_unsync_page(vcpu->kvm, s); + flush = true; + } + + if (flush) + kvm_mmu_flush_tlb(vcpu); +} + struct mmu_page_path { struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1]; unsigned int idx[PT64_ROOT_LEVEL-1]; @@ -1318,8 +1347,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, unsigned index; unsigned quadrant; struct hlist_head *bucket; - struct kvm_mmu_page *sp, *unsync_sp = NULL; + struct kvm_mmu_page *sp; struct hlist_node *node, *tmp; + bool need_sync = false; role = vcpu->arch.mmu.base_role; role.level = level; @@ -1336,17 +1366,14 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, bucket = &vcpu->kvm->arch.mmu_page_hash[index]; hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link) if (sp->gfn == gfn) { - if (sp->unsync) - unsync_sp = sp; + if (!need_sync && sp->unsync) + need_sync = true; if (sp->role.word != role.word) continue; - if (!direct && unsync_sp && - kvm_sync_page_transient(vcpu, unsync_sp)) { - unsync_sp = NULL; + if (sp->unsync && kvm_sync_page_transient(vcpu, sp)) break; - } mmu_page_add_parent_pte(vcpu, sp, parent_pte); if (sp->unsync_children) { @@ -1358,9 +1385,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, trace_kvm_mmu_get_page(sp, false); return sp; } - if (!direct && unsync_sp) - kvm_sync_page(vcpu, unsync_sp); - ++vcpu->kvm->stat.mmu_cache_miss; sp = kvm_mmu_alloc_page(vcpu, parent_pte); if (!sp) @@ -1371,6 +1395,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, if (!direct) { if (rmap_write_protect(vcpu->kvm, gfn)) kvm_flush_remote_tlbs(vcpu->kvm); + if (level > PT_PAGE_TABLE_LEVEL && need_sync) + kvm_sync_pages(vcpu, gfn); + account_shadowed(vcpu->kvm, gfn); } if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) -- GitLab